GROUPING_ID (Transact-SQL)

THIS TOPIC APPLIES TO:yesSQL Server (starting with 2008)yesAzure SQL DatabasenoAzure SQL Data Warehouse noParallel Data Warehouse

Is a function that computes the level of grouping. GROUPING_ID can be used only in the SELECT <select> list, HAVING, or ORDER BY clauses when GROUP BY is specified.

Topic link icon Transact-SQL Syntax Conventions

Syntax


GROUPING_ID ( <column_expression>[ ,...n ] )  

Arguments


Is a column_expression in a GROUP BY clause.

Return Type

int

Remarks

The GROUPING_ID must exactly match the expression in the GROUP BY list. For example, if you are grouping by DATEPART (yyyy, <column name>), use GROUPING_ID (DATEPART (yyyy, <column name>)); or if you are grouping by <column name>, use GROUPING_ID (<column name>).

Comparing GROUPING_ID () to GROUPING ()

GROUPING_ID ( [ ,...n ]) inputs the equivalent of the GROUPING () return for each column in its column list in each output row as a string of ones and zeros. GROUPING_ID interprets that string as a base-2 number and returns the equivalent integer. For example consider the following statement: SELECT a, b, c, SUM(d),``GROUPING_ID(a,b,c)``FROM T GROUP BY <group by list>. The following table shows the GROUPING_ID () input and output values.

Columns aggregated GROUPING_ID (a, b, c) input = GROUPING(a) + GROUPING(b) + GROUPING(c) GROUPING_ID () output
a 100 4
b 010 2
c 001 1
ab 110 6
ac 101 5
bc 011 3
abc 111 7

Technical Definition of GROUPING_ID ()

Each GROUPING_ID argument must be an element of the GROUP BY list. GROUPING_ID () returns an integer bitmap whose lowest N bits may be lit. A lit bit indicates the corresponding argument is not a grouping column for the given output row. The lowest-order bit corresponds to argument N, and the N-1th lowest-order bit corresponds to argument 1.

GROUPING_ID () Equivalents

For a single grouping query, GROUPING () is equivalent to GROUPING_ID (), and both return 0.

For example, the following statements are equivalent:

Statement A:

SELECT GROUPING_ID(A,B)  
FROM T   
GROUP BY CUBE(A,B)   

Statement B:

SELECT 3 FROM T GROUP BY ()  
UNION ALL  
SELECT 1 FROM T GROUP BY A  
UNION ALL  
SELECT 2 FROM T GROUP BY B  
UNION ALL  
SELECT 0 FROM T GROUP BY A,B  

Examples

A. Using GROUPING_ID to identify grouping levels

The following example returns the count of employees by Name and Title, Name, and company total in the AdventureWorks2012 database. GROUPING_ID() is used to create a value for each row in the Title column that identifies its level of aggregation.

SELECT D.Name  
    ,CASE   
    WHEN GROUPING_ID(D.Name, E.JobTitle) = 0 THEN E.JobTitle  
    WHEN GROUPING_ID(D.Name, E.JobTitle) = 1 THEN N'Total: ' + D.Name   
    WHEN GROUPING_ID(D.Name, E.JobTitle) = 3 THEN N'Company Total:'  
        ELSE N'Unknown'  
    END AS N'Job Title'  
    ,COUNT(E.BusinessEntityID) AS N'Employee Count'  
FROM HumanResources.Employee E  
    INNER JOIN HumanResources.EmployeeDepartmentHistory DH  
        ON E.BusinessEntityID = DH.BusinessEntityID  
    INNER JOIN HumanResources.Department D  
        ON D.DepartmentID = DH.DepartmentID       
WHERE DH.EndDate IS NULL  
    AND D.DepartmentID IN (12,14)  
GROUP BY ROLLUP(D.Name, E.JobTitle);  

B. Using GROUPING_ID to filter a result set

Simple Example

In the following code, to return only the rows that have a count of employees by title, remove the comment characters from HAVING GROUPING_ID(D.Name, E.JobTitle); = 0 in the AdventureWorks2012 database. To return only rows with a count of employees by department, remove the comment characters from HAVING GROUPING_ID(D.Name, E.JobTitle) = 1;.

SELECT D.Name  
    ,E.JobTitle  
    ,GROUPING_ID(D.Name, E.JobTitle) AS 'Grouping Level'  
    ,COUNT(E.BusinessEntityID) AS N'Employee Count'  
FROM HumanResources.Employee AS E  
    INNER JOIN HumanResources.EmployeeDepartmentHistory AS DH  
        ON E.BusinessEntityID = DH.BusinessEntityID  
    INNER JOIN HumanResources.Department AS D  
        ON D.DepartmentID = DH.DepartmentID       
WHERE DH.EndDate IS NULL  
    AND D.DepartmentID IN (12,14)  
GROUP BY ROLLUP(D.Name, E.JobTitle)  
--HAVING GROUPING_ID(D.Name, E.JobTitle) = 0; --All titles  
--HAVING GROUPING_ID(D.Name, E.JobTitle) = 1; --Group by Name;  

Here is the unfiltered result set.

Name Title Grouping Level Employee Count Name
Document Control Control Specialist 0 2 Document Control
Document Control Document Control Assistant 0 2 Document Control
Document Control Document Control Manager 0 1 Document Control
Document Control NULL 1 5 Document Control
Facilities and Maintenance Facilities Administrative Assistant 0 1 Facilities and Maintenance
Facilities and Maintenance Facilities Manager 0 1 Facilities and Maintenance
Facilities and Maintenance Janitor 0 4 Facilities and Maintenance
Facilities and Maintenance Maintenance Supervisor 0 1 Facilities and Maintenance
Facilities and Maintenance NULL 1 7 Facilities and Maintenance
NULL NULL 3 12 NULL

Complex Example

The following example uses GROUPING_ID() to filter a result set that contains multiple grouping levels by grouping level. Similar code can be used to create a view that has several grouping levels and a stored procedure that calls the view by passing a parameter that filters the view by grouping level. The example uses the AdventureWorks2012 database.

DECLARE @Grouping nvarchar(50);  
DECLARE @GroupingLevel smallint;  
SET @Grouping = N'CountryRegionCode Total';  

SELECT @GroupingLevel = (  
    CASE @Grouping  
        WHEN N'Grand Total'             THEN 15  
        WHEN N'SalesPerson Total'       THEN 14  
        WHEN N'Store Total'             THEN 13  
        WHEN N'Store SalesPerson Total' THEN 12  
        WHEN N'CountryRegionCode Total' THEN 11  
        WHEN N'Group Total'             THEN 7  
        ELSE N'Unknown'  
    END);  

SELECT   
    T.[Group]  
    ,T.CountryRegionCode  
    ,S.Name AS N'Store'  
    ,(SELECT P.FirstName + ' ' + P.LastName   
        FROM Person.Person AS P   
        WHERE P.BusinessEntityID = H.SalesPersonID)  
        AS N'Sales Person'  
    ,SUM(TotalDue)AS N'TotalSold'  
    ,CAST(GROUPING(T.[Group])AS char(1)) +   
        CAST(GROUPING(T.CountryRegionCode)AS char(1)) +   
        CAST(GROUPING(S.Name)AS char(1)) +   
        CAST(GROUPING(H.SalesPersonID)AS char(1))   
        AS N'GROUPING base-2'  
    ,GROUPING_ID((T.[Group])  
        ,(T.CountryRegionCode),(S.Name),(H.SalesPersonID)  
        ) AS N'GROUPING_ID'  
    ,CASE   
        WHEN GROUPING_ID(  
            (T.[Group]),(T.CountryRegionCode)  
            ,(S.Name),(H.SalesPersonID)  
            ) = 15 THEN N'Grand Total'  
        WHEN GROUPING_ID(  
            (T.[Group]),(T.CountryRegionCode)  
            ,(S.Name),(H.SalesPersonID)  
            ) = 14 THEN N'SalesPerson Total'  
        WHEN GROUPING_ID(  
            (T.[Group]),(T.CountryRegionCode)  
            ,(S.Name),(H.SalesPersonID)  
            ) = 13 THEN N'Store Total'  
        WHEN GROUPING_ID(  
            (T.[Group]),(T.CountryRegionCode)  
            ,(S.Name),(H.SalesPersonID)  
            ) = 12 THEN N'Store SalesPerson Total'  
        WHEN GROUPING_ID(  
            (T.[Group]),(T.CountryRegionCode)  
            ,(S.Name),(H.SalesPersonID)  
            ) = 11 THEN N'CountryRegionCode Total'  
        WHEN GROUPING_ID(  
            (T.[Group]),(T.CountryRegionCode)  
            ,(S.Name),(H.SalesPersonID)  
            ) =  7 THEN N'Group Total'  
        ELSE N'Error'  
        END AS N'Level'  
FROM Sales.Customer AS C  
    INNER JOIN Sales.Store AS S  
        ON C.StoreID  = S.BusinessEntityID   
    INNER JOIN Sales.SalesTerritory AS T  
        ON C.TerritoryID  = T.TerritoryID   
    INNER JOIN Sales.SalesOrderHeader AS H  
        ON C.CustomerID = H.CustomerID  
GROUP BY GROUPING SETS ((S.Name,H.SalesPersonID)  
    ,(H.SalesPersonID),(S.Name)  
    ,(T.[Group]),(T.CountryRegionCode),()  
    )  
HAVING GROUPING_ID(  
    (T.[Group]),(T.CountryRegionCode),(S.Name),(H.SalesPersonID)  
    ) = @GroupingLevel  
ORDER BY   
    GROUPING_ID(S.Name,H.SalesPersonID),GROUPING_ID((T.[Group])  
    ,(T.CountryRegionCode)  
    ,(S.Name)  
    ,(H.SalesPersonID))ASC;  

C. Using GROUPING_ID () with ROLLUP and CUBE to identify grouping levels

The code in the following examples show using GROUPING() to compute the Bit Vector(base-2) column. GROUPING_ID() is used to compute the corresponding Integer Equivalent column. The column order in the GROUPING_ID() function is the opposite of the column order of the columns that are concatenated by the GROUPING() function.

In these examples, GROUPING_ID() is used to create a value for each row in the Grouping Level column to identify the level of grouping. Grouping levels are not always a consecutive list of integers that start with 1 (0, 1, 2,...n).

Note

GROUPING and GROUPING_ID can be used n a HAVING clause to filter a result set.

ROLLUP Example

In this example, all grouping levels do not appear as they do in the following CUBE example. If the order of the columns in the ROLLUP list is changed, the level values in the Grouping Level column will also have to be changed. The example uses the AdventureWorks2012 database.

SELECT DATEPART(yyyy,OrderDate) AS N'Year'  
    ,DATEPART(mm,OrderDate) AS N'Month'  
    ,DATEPART(dd,OrderDate) AS N'Day'  
    ,SUM(TotalDue) AS N'Total Due'  
    ,CAST(GROUPING(DATEPART(dd,OrderDate))AS char(1)) +   
        CAST(GROUPING(DATEPART(mm,OrderDate))AS char(1)) +   
        CAST(GROUPING(DATEPART(yyyy,OrderDate))AS char(1))   
     AS N'Bit Vector(base-2)'  
    ,GROUPING_ID(DATEPART(yyyy,OrderDate)  
        ,DATEPART(mm,OrderDate)  
        ,DATEPART(dd,OrderDate))   
        AS N'Integer Equivalent'  
    ,CASE  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)  
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 0 THEN N'Year Month Day'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)  
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 1 THEN N'Year Month'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)  
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 2 THEN N'not used'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)  
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 3 THEN N'Year'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)  
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 4 THEN N'not used'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)  
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 5 THEN N'not used'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)  
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 6 THEN N'not used'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)  
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 7 THEN N'Grand Total'  
    ELSE N'Error'  
    END AS N'Grouping Level'  
FROM Sales.SalesOrderHeader  
WHERE DATEPART(yyyy,OrderDate) IN(N'2007',N'2008')  
    AND DATEPART(mm,OrderDate) IN(1,2)  
    AND DATEPART(dd,OrderDate) IN(1,2)  
GROUP BY ROLLUP(DATEPART(yyyy,OrderDate)  
        ,DATEPART(mm,OrderDate)  
        ,DATEPART(dd,OrderDate))  
ORDER BY GROUPING_ID(DATEPART(mm,OrderDate)  
    ,DATEPART(yyyy,OrderDate)  
    ,DATEPART(dd,OrderDate)  
    )  
    ,DATEPART(yyyy,OrderDate)  
    ,DATEPART(mm,OrderDate)  
    ,DATEPART(dd,OrderDate);  

Here is a partial result set.

Year Month Day Total Due Bit Vector (base-2) Integer Equivalent Grouping Level
2007 1 1 1497452.6066 000 0 Year Month Day
2007 1 2 21772.3494 000 0 Year Month Day
2007 2 1 2705653.5913 000 0 Year Month Day
2007 2 2 21684.4068 000 0 Year Month Day
2008 1 1 1908122.0967 000 0 Year Month Day
2008 1 2 46458.0691 000 0 Year Month Day
2008 2 1 3108771.9729 000 0 Year Month Day
2008 2 2 54598.5488 000 0 Year Month Day
2007 1 NULL 1519224.956 100 1 Year Month
2007 2 NULL 2727337.9981 100 1 Year Month
2008 1 NULL 1954580.1658 100 1 Year Month
2008 2 NULL 3163370.5217 100 1 Year Month
2007 NULL NULL 4246562.9541 110 3 Year
2008 NULL NULL 5117950.6875 110 3 Year
NULL NULL NULL 9364513.6416 111 7 Grand Total

CUBE Example

In this example, the GROUPING_ID() function is used to create a value for each row in the Grouping Level column to identify the level of grouping.

Unlike ROLLUP in the previous example, CUBE outputs all grouping levels. If the order of the columns in the CUBE list is changed, the level values in the Grouping Level column will also have to be changed. The example uses the AdventureWorks2012 database

SELECT DATEPART(yyyy,OrderDate) AS N'Year'  
    ,DATEPART(mm,OrderDate) AS N'Month'  
    ,DATEPART(dd,OrderDate) AS N'Day'  
    ,SUM(TotalDue) AS N'Total Due'  
    ,CAST(GROUPING(DATEPART(dd,OrderDate))AS char(1)) +   
        CAST(GROUPING(DATEPART(mm,OrderDate))AS char(1)) +   
        CAST(GROUPING(DATEPART(yyyy,OrderDate))AS char(1))   
        AS N'Bit Vector(base-2)'  
    ,GROUPING_ID(DATEPART(yyyy,OrderDate)  
        ,DATEPART(mm,OrderDate)  
        ,DATEPART(dd,OrderDate))   
        AS N'Integer Equivalent'  
    ,CASE  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)  
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 0 THEN N'Year Month Day'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)   
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 1 THEN N'Year Month'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)   
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 2 THEN N'Year Day'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)   
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 3 THEN N'Year'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)   
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 4 THEN N'Month Day'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)   
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 5 THEN N'Month'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)   
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 6 THEN N'Day'  
        WHEN GROUPING_ID(DATEPART(yyyy,OrderDate)   
            ,DATEPART(mm,OrderDate),DATEPART(dd,OrderDate)  
            ) = 7 THEN N'Grand Total'  
    ELSE N'Error'  
    END AS N'Grouping Level'  
FROM Sales.SalesOrderHeader  
WHERE DATEPART(yyyy,OrderDate) IN(N'2007',N'2008')  
    AND DATEPART(mm,OrderDate) IN(1,2)  
    AND DATEPART(dd,OrderDate) IN(1,2)  
GROUP BY CUBE(DATEPART(yyyy,OrderDate)  
    ,DATEPART(mm,OrderDate)  
    ,DATEPART(dd,OrderDate))  
ORDER BY GROUPING_ID(DATEPART(yyyy,OrderDate)  
    ,DATEPART(mm,OrderDate)  
    ,DATEPART(dd,OrderDate)  
    )  
    ,DATEPART(yyyy,OrderDate)  
    ,DATEPART(mm,OrderDate)  
    ,DATEPART(dd,OrderDate);  

Here is a partial result set.

Year Month Day Total Due Bit Vector (base-2) Integer Equivalent Grouping Level
2007 1 1 1497452.6066 000 0 Year Month Day
2007 1 2 21772.3494 000 0 Year Month Day
2007 2 1 2705653.5913 000 0 Year Month Day
2007 2 2 21684.4068 000 0 Year Month Day
2008 1 1 1908122.0967 000 0 Year Month Day
2008 1 2 46458.0691 000 0 Year Month Day
2008 2 1 3108771.9729 000 0 Year Month Day
2008 2 2 54598.5488 000 0 Year Month Day
2007 1 NULL 1519224.956 100 1 Year Month
2007 2 NULL 2727337.9981 100 1 Year Month
2008 1 NULL 1954580.1658 100 1 Year Month
2008 2 NULL 3163370.5217 100 1 Year Month
2007 NULL 1 4203106.1979 010 2 Year Day
2007 NULL 2 43456.7562 010 2 Year Day
2008 NULL 1 5016894.0696 010 2 Year Day
2008 NULL 2 101056.6179 010 2 Year Day
2007 NULL NULL 4246562.9541 110 3 Year
2008 NULL NULL 5117950.6875 110 3 Year
NULL 1 1 3405574.7033 001 4 Month Day
NULL 1 2 68230.4185 001 4 Month Day
NULL 2 1 5814425.5642 001 4 Month Day
NULL 2 2 76282.9556 001 4 Month Day
NULL 1 NULL 3473805.1218 101 5 Month
NULL 2 NULL 5890708.5198 101 5 Month
NULL NULL 1 9220000.2675 011 6 Day
NULL NULL 2 144513.3741 011 6 Day
NULL NULL NULL 9364513.6416 111 7 Grand Total

See Also

GROUPING (Transact-SQL)
GROUP BY (Transact-SQL)